Binary Counter

This is a binary counter. Watch how the individual bits change - the least significant bit (i.e. the units, on the right) flips every time the number changes, but the next column changes every two numbers, the column after that every four, and so on. The digits trailing away below the counter show the history of each bit.

You can use this knowledge to help you to quickly write a sequence of binary numbers, but also to help you to fill in the inputs for a truth table (see Boolean logic). You could even implement this technique using nested loops to create your own binary counter in Python.